Elongated slender and generally flexible drainage tubes commonly are axially inserted into body cavities for removal of fluid therefrom (liquid gastric secretions, gases, etc.). Generally, a suction/fluid collection system is connected to the proximal end of the drainage tube to facilitate drainage. In medical or hospital settings, a drainage tube might be inserted via the nasal passage or mouth through the esophagus to extend into the stomach or intestines, operable to retrieve unwanted fluid contents therefrom; and such a fluid drainage device is commonly known as a nasogastric tube.
The importance of continuous operation of an inserted drainage (or a nasoquastic) tube cannot be over estimated, such as in a patient who is obtunded, with intestinal obstruction, or is post-operative; as inadequate removal of unwanted gastric fluids can result in pneumonia, intestinal distention, morbidity, gastric wall trauma and bleeding, or even death.
One conventional form of dual lumen drainage tube 10 is illustrated in FIG. 1 herein, having a single exterior tube body 12 with wall structure that define dual lumens 14, 16 (or separated axially extended side-by-side passages). The passage 14 may branch off of the main body 12 via tubing 18 to a proximal end fitting 20 having at least one opening serving as inlet opening to the lumen 14. The passage 16 might extend to the proximal end of the main body, to a fitting 22 that presents outlet opening from lumen 16. The lumens 14, 16 are communicated together only via a small cross-over opening 24 in the tube wall structure at the distal tube end. The exterior tube wall adjacent its distal end has small holes 26 that open to the suction lumen 16. The lumen passages 14, 16 are of different cross-sectional areas: larger passage 16 serving as the suction or sump lumen and smaller passage 14 serving as the vent or makeup air lumen.
Suction/fluid collection system 28 (schematically illustrated only) can be connected via flexible transparent tubing 30 to the proximal end fitting 22 of the suction lumen. The opening in the makeup air lumen proximal end fitting 20 would be the atmospheric air, or could be contoured to accept a luer tip or the like for allowing easy connection via the inlet lumen 14 for syringe injection of fluids into the patient, or could provide for the connection of an antireflux valve (not shown).
After the distal end of the gastric tube 10 is axially inserted via the nose or mouth to position the side holes proximate the region within the patient to be drained, operation of the suction/fluid collection system 28 and reduced pressures in the suction lumen 16 would effectively withdraw proximate body fluids through the distal end tube side holes 26 and via the suction lumen 16 to the collection system; and the withdrawn fluids would also include atmospheric air inflowing via the makeup air vent lumen 14 and cross-over opening 24. This continuous air and retrieved body fluid flow via the drainage or suction lumen 16 helps prevent blockage of the distal tube end side holes and trauma to the stomach wall from excessive suction, while removing the body fluids as needed.
However, blockage of either the distal tube end side holes 26 or the suction lumen 16 by the retrieved fluid contents will result in reduced or total stoppage of proper fluid removal. Thus, close regular monitoring of continued drainage system operation is required.
Current methods of monitoring gastric tube function are subjective and imprecise. One presently used monitoring technique is visual, observing through the typically transparent suction tubing 30 the movement therein of the retrieved fluids flowing away from the drainage tube 10 and toward the suction/fluid collection system 28. This is not precise or reliable as: movement of a solidly filled tubing is difficult to perceive; the movement of fluid plugs might be slow or irregular; or a completely void tubing would be meaningless, as such could occur when there is no drainage flow (an acceptable situation) or when there is no air flow (not an acceptable situation). Also, detected fluid movement can be deceiving in that some minimal movement can occur in a poorly functioning tube. Another commonly used monitoring technique is audible, by having an attendant listen for whistling sounds of the makeup air flowing into the tubing opening of the makeup air lumen 14. However, proximate noises can make this detection effort difficult and/or insensitive; while it further requires the special time consuming individual services of an attendant.
This invention provides for improved monitoring of the operation of a body fluid dual lumen drainage system.
Basic objects of this invention are to provide apparatus and method for accurately, economically, easily and reliably monitoring a dual lumen drainage system (such as with a nasogastric tube.
Another object of this invention is to provide apparatus and method for monitoring a dual lumen drainage system that is simple, inexpensive, effective continuously, easily observed, and further can be incorporated into most conventionally used existing dual lumen body cavity drainage systems.
Another object of the invention is to route atmospheric air needed for venting a dual lumen medical drainage tube through a sealed transparent vessel partially filled with a safe transparent liquid, such as water, whereby resulting air flow is as bubbles rising through the vessel liquid, easily visible for offering assurance of proper functioning of the drainage tube.